Integumentary System

dermatology

Study and treatment of integumentary system

Composition of Integumentary System

the skin (integument), hair, nails, and cutaneous glands

epidermis

superficial layer - epitheliel tissue

dermis

secondary layer - connective tissue

hypodermis

connective tissue underneath skin

features of thick skin

“acral”, hairless, no sebaceous glands

features of thin skin

hairy, has sebaceous and sweat glands

functions of skin

trauma/infection resistance, water retention, synthesis of vitamin D, sensation, thermoregulation, nonverbal communication

epidermis tissue type

keratinized stratified squamos; superficial cells are dead

epidermis nutrient access

avascular, sparse nerve endings

cells of epidermis

keratinocytes, stem cells, melanocytes, tactile(merkel) cells, dendritic (langerhans) cells

functions of keratinocytes

synthesize keratin, and store melanin to protect DNA from UV

location of keratinocytes

epidermis - many layers

function of stem cells

divide and produce keratinocytes

location of stem cells

stratum basale

function of melanocytes

makes melanin, which is stored by keratinocytes to protect their DNA from UV

location of melanocytes

stratum basale

function of tactile (merkel) cells

touch receptors that join with nerves

location of tactile (merkel) cells

stratum basale

function of dendritic (langerhans) cells

immune surveillance

location of dendritic (langerhans) cells

stratum spinosum, stratum granulosum

layers of epidermis (superficial to deep)

stratum corneum

stratum lucidum

stratum granulosum

stratum spinosum

stratum basale

stratum basale

deepest layer of epidermis; one cell thick

stratum spinosum

second deepest layer of epidermis; several layers of cell; thickest layer

stratum granulosum

third deepest layer of epidermis; cells have dark granules

stratum lucidum

fourth deepest layer of epidermis; cells lack organelles

stratum corneum

apical layer of epidermis; Several layers of dead, scaly cells

composition of dermis

rich in collagen fibers, large blood supply, cutaneous glands, hair follicles, arrector muscles, and nail roots

layers of dermis

papillary

reticular

Papillary layer of dermis

superficial, thin layer, areolar connective tissue, rich in blood vessels

Reticular layer of dermis

deep; dense irregular connective tissue; Striae (stretch marks): stretching of the dermal collagen

hypodermis

not true skin layer; adipose and areolar tissue

functions of hypodermis

energy storage, thermal insulation, connection to muscle/bone

diagnostic skin colors

cyanotic, erythema, pallor, albinism, jaundice, hematoma

cyanosis

lack of oxygen

erythema

redness, increased blood flow

pallor

pale/ashen, reduced blood flow

albinism

white, genetic lack of melatonin

jaundice

yellow, liver and bilirubin

hematoma

bruise

friction ridges of fingertips

aids in sensitivity to texture and ability to grasp; causes fingerprints

flexion lines

where skin near joint attaches to deeper tissue

freckles

flat/melanized patches; varies with hereditary and UV exposure

mole

elevated patch of melanized skin

hemangiomas

discolored skin (birthmarks) caused by benign tumors of capillaries

hair (pilus)

filament of keratinized cells that grow from a hair follicle on thin skin

three types of hair/pilus

downy hair(lanugo), vellus hair, terminal hair

downy hair (lanugo)

Fine, downy, unpigmented hair of fetus

vellus hair

Fine and unpigmented, 2/3 hair of women, 1/10 hair of men, all hair of children except eyebrows, eyelashes, and scalp

terminal

Coarse and pigmented; includes eyebrows, eyelashes,

and scalp; after puberty has axillary, pubic, male facial hair, some hair on trunk and limbs

nails

derivatives of stratum corneum; composed of very thin, dead, scaly cells with parallel rows of hard keratin

three parts of a nail

nail plate, nail fold, nail bed

nail plate

free edge, nail body, nail root

nail fold

nail groove

nail bed

hyponychium, nail matrix, lunule/lunula, and eponychium (cuticle)

types of cutaneous glands

Sweat (Sudoriferous) Glands, Sebaceous Glands, Ceruminous Glands, Mammary Glands

types of sudoriferous glands

apocrine and eccrine(merocrine) glands

functions of apocrine glands

Ducts open into hair follicle; produces sweat composed of many fatty acids (bacterial metabolism of those fats causes odor); responsive to stress and sexual stimulation; develop in puberty; believed to secrete pheromones

eccrine (merocrine) glands

simple ducts lead to pores at skin surface; produce watery perspiration to cool body; contains some wastes found in urine

location of apocrine glands

groin, anal region, axilla, areola and beard

location of eccrine glands

numerous, widespread, and especially abundant on palms, soles, and forehead

sebaceous glands

produces sebum(oily secretion) that open into hair follicles, holocrine secretion (fill up with sebum until they burst); keeps hair from becoming brittle

ceruminous glands

found in auditory canal; produces cerumen/earwax which is a combination of sebum and dead skin cells

function of ceruminous glands

keeps eardrum pliable, waterproofs canal, kills bacteria, and coats guard hairs

mammary glands

develop during pregnancy and lactation; modified apocrine gland

aging affects on skin

Hair turns grayer and thinner

• Melanocyte stem cells die out

• Mitosis slows down

• Dead hairs not replaced

• Atrophy of sebaceous glands

• Skin becomes thinner and more translucent

aging affects on blood supply and skin

• Fewer and more fragile vessels

• Rosacea; Dilated blood vessels that cause reddened areas.

• Increased bruising

aging affects on thermoregulation

Vulnerability to hypothermia and heat stroke

what is acne

inflammation of the sebaceous glands, follicle becomes blocked with keratinocytes and sebum and develops into a blackhead

disorders of integuementary system

acne, dermatitis, eczema, psoriasis, ringworm, rosacea, warts

what is dermatitis

Any inflammation of the skin, typically marked by itching and redness; often caused by contact, caused by exposure to toxins such as poison ivy.

what is eczema

Itchy, red, "weeping" skin lesions caused by an allergy, usually beginning before age 5; may progress to thickened, leathery, darkly pigmented patches of skin.

what is psoriasis

Recurring, reddened plaques covered with silvery scale; sometimes disfiguring; possibly caused by an autoimmune response; runs in families.

what is ringworm

A fungal infection of the skin (not a worm) that sometimes grows in a circular pattern; common in moist areas such as the axilla, groin, and foot (athlete's foot).

what is rosacea

A red rashlike area, often in the area of the nose and cheeks, marked by fine networks of dilated blood vessels; worsened by hot drinks, alcohol, and spicy food

what are warts

Benign, elevated, rough lesions caused by human papillomaviruses (HPV)

three types of skin cancer

basal cell carcinoma, squamous cell carcinoma, and malignant melanoma

basal cell carcinoma

most common, yet least dangerous; rarely metastasizes, arises in stratum basale & invades dermis

squamous cell carcinoma

Arises from keratinocytes of stratum spinosum; can metastasize to

lymph nodes; potentially fatal

malignant melanoma

Most deadly; arises from melanocyte of existing mole (nevus); metastasizes quickly & often fatal if not treated quickly

death from burns caused by…

fluid loss leads to dehydration; infection leads to sepsis; toxic effects of eschar(dead tissue) not removed from skin

first-degree burn (partial thickness)

Only epidermis; Usually localized; Redness, slight edema, and pain

Ex: Sunburn

second-degree burn (partial thickness)

-epidermis and part of dermis

-red, tan, or white

-blistered and painful

-may damage hair follicles, nerve endings, and cutaneous glands

Ex: Severe sunburns and scalds

third-degree burn (full thickness)

-Epidermis and dermis are completely destroyed

-Contracture (abnormal fibrosis) and disfigurement can result

-Bones/ muscles/tendons may beaffected

ABCDE for melanoma identification

A - assymetry

B - border

C - color

D - diameter (bigger than 6mm is concerning)

E - evolution